1. Technical Field
The present invention relates to a sampling frequency conversion apparatus preferable for digital audio equipment or the like.
2. Background Art
In the field of digital audios or the like, since devices supporting various sampling frequencies are provided, devices that are different from each other in terms of the sampling frequency are often connected to each other. In this case, a sampling frequency conversion apparatus is interposed between a preceding device and a succeeding device for converting an input sampling frequency of input samples such as audio samples which are fed from the preceding device to an output sampling frequency which is specified by the succeeding device.
A known sampling frequency conversion apparatus applies an interpolative operation to input samples having the input sampling frequency so as to compute interpolated samples having the output sampling frequency which is specified by the succeeding device, and outs the interpolated samples to the succeeding device. Incidentally, as a literature concerning such a type of the sampling frequency conversion apparatus, there are, for example, patent documents 1 and 2.
[Patent Document 1] JP-A-2006-238044
[Patent Document 2] JP-A-2006-261812
However, in case that the output sampling frequency requested by the succeeding device is equal to or greater than the input sampling frequency of the input samples, the conventional sampling frequency conversion apparatus occasionally fails to convert the sampling frequency due to occurrence of errors in the interpolative operation. Even in case that the output sampling frequency requested by the succeeding device is smaller than the input sampling frequency of the input samples, the conventional sampling frequency conversion apparatus may fail to convert the sampling frequency due to occurrence of jitter of the sampling frequencies.